From ba32bd95d431525ad2ffac97cadf9ee40b63939e Mon Sep 17 00:00:00 2001 From: Brandon Philips Date: Thu, 27 Sep 2007 20:55:17 -0300 Subject: [PATCH] V4L/DVB (6275): V4L: vivi.c remove the "resource" locking The "resource" locking in vivi isn't needed since streamon/streamoff/read_stream do mutual exclusion using q->reading/q->streaming. Plus it is sort of broken: a) res_locked() use in vivi_read() is racey. b) res_free() calls mutex_lock twice causing streamoff to break Signed-off-by: Brandon Philips Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/vivi.c | 48 ++++---------------------------------- 1 file changed, 4 insertions(+), 44 deletions(-) diff --git a/drivers/media/video/vivi.c b/drivers/media/video/vivi.c index cdef622f6b32..82755091648b 100644 --- a/drivers/media/video/vivi.c +++ b/drivers/media/video/vivi.c @@ -170,7 +170,6 @@ struct vivi_dev { int users; /* various device info */ - unsigned int resources; struct video_device vfd; struct vivi_dmaqueue vidq; @@ -726,40 +725,6 @@ static struct videobuf_queue_ops vivi_video_qops = { .buf_release = buffer_release, }; -/* ------------------------------------------------------------------ - IOCTL handling - ------------------------------------------------------------------*/ - - -static int res_get(struct vivi_dev *dev, struct vivi_fh *fh) -{ - /* is it free? */ - mutex_lock(&dev->lock); - if (dev->resources) { - /* no, someone else uses it */ - mutex_unlock(&dev->lock); - return 0; - } - /* it's free, grab it */ - dev->resources =1; - dprintk(1,"res: get\n"); - mutex_unlock(&dev->lock); - return 1; -} - -static int res_locked(struct vivi_dev *dev) -{ - return (dev->resources); -} - -static void res_free(struct vivi_dev *dev, struct vivi_fh *fh) -{ - mutex_lock(&dev->lock); - dev->resources = 0; - dprintk(1,"res: put\n"); - mutex_lock(&dev->lock); -} - /* ------------------------------------------------------------------ IOCTL vidioc handling ------------------------------------------------------------------*/ @@ -913,9 +878,7 @@ static int vidioc_streamon(struct file *file, void *priv, enum v4l2_buf_type i) if (i != fh->type) return -EINVAL; - if (!res_get(dev,fh)) - return -EBUSY; - return (videobuf_streamon(&fh->vb_vidq)); + return videobuf_streamon(&fh->vb_vidq); } static int vidioc_streamoff(struct file *file, void *priv, enum v4l2_buf_type i) @@ -928,10 +891,7 @@ static int vidioc_streamoff(struct file *file, void *priv, enum v4l2_buf_type i) if (i != fh->type) return -EINVAL; - videobuf_streamoff(&fh->vb_vidq); - res_free(dev,fh); - - return (0); + return videobuf_streamoff(&fh->vb_vidq); } static int vidioc_s_std (struct file *file, void *priv, v4l2_std_id *i) @@ -1096,10 +1056,10 @@ static ssize_t vivi_read(struct file *file, char __user *data, size_t count, loff_t *ppos) { struct vivi_fh *fh = file->private_data; + struct vivi_dev *dev = fh->dev; + struct videobuf_queue *q = &fh->vb_vidq; if (fh->type==V4L2_BUF_TYPE_VIDEO_CAPTURE) { - if (res_locked(fh->dev)) - return -EBUSY; return videobuf_read_stream(&fh->vb_vidq, data, count, ppos, 0, file->f_flags & O_NONBLOCK); } -- 2.20.1